Circuit structure and manufacturing method thereof

ABSTRACT

A manufacturing method of a circuit board structure is described as follows. An inner circuit structure including a core layer having an upper and an opposite lower surface, a first patterned circuit layer disposed on the upper surface and a second patterned circuit layer disposed on the lower surface is provided. An insulating material layer is formed on a portion of the first patterned circuit layer. A laser resisting layer is formed on at least a portion of the insulating material layer. A release layer is adhered to the laser resisting layer. A build-up process is performed so as to laminate a first and a second build-up circuit structures on the first and the second patterned circuit layers, respectively. A laser ablation process is performed on the first build-up circuit structure so as to form a cavity at least exposing a portion of the upper surface of the core layer.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of Taiwan applicationserial no. 104140604, filed on Dec. 3, 2015. The entirety of theabove-mentioned patent application is hereby incorporated by referenceherein and made a part of this specification.

BACKGROUND OF THE INVENTION

Field of the Invention

The invention relates to a circuit board structure and a manufacturingmethod thereof. More particularly, the invention relates to a circuitboard structure having a cavity and a manufacturing method thereof.

Description of Related Art

Generally, to manufacture a circuit board structure having a cavity, itis necessary to fabricate an alignment copper layer on a core layer ofan inner circuit layer. The purpose thereof is that during a subsequentprocess of forming the cavity by performing laser ablation on thecircuit structure, the alignment copper layer serves not only as a laserresisting layer for preventing excessive ablation of the circuitstructure, but also as a laser alignment pattern that facilitates thelaser ablation process. However, since the alignment copper layer isdirectly formed on the core layer of the inner circuit layer, thecircuit layout of the core layer is limited, thus reducing layoutflexibility of the core layer.

SUMMARY OF THE INVENTION

The invention provides a circuit board structure having better layoutflexibility.

The invention also provides a manufacturing method of a circuit boardstructure used for manufacturing the above-mentioned circuit boardstructure.

The manufacturing method of a circuit board structure of the inventionincludes the following manufacturing steps. An inner circuit structureis provided. The inner circuit structure includes a core layer having anupper surface and an opposite lower surface, a first patterned circuitlayer disposed on the upper surface and a second patterned circuit layerdisposed on the lower surface. An insulating material layer is formed ona portion of the first patterned circuit layer, wherein the insulatingmaterial layer covers a portion of the upper surface. A laser resistinglayer is formed on at least a portion of the insulating material layer.A release layer is adhered to at least the laser resisting layer. Abuild-up process is performed so as to laminate a first build-up circuitstructure and a second build-up circuit structure on the first patternedcircuit layer and the second patterned circuit layer, respectively,wherein the first build-up circuit structure covers the release layer. Alaser ablation process is performed on the first build-up circuitstructure to irradiate a laser beam on the laser resisting layer so asto remove a portion of the first build-up circuit structure and therelease layer, and thereby a cavity at least exposing a portion of theupper surface of the core layer is formed.

In an embodiment of the invention, the step of forming the insulatingmaterial layer includes the following. A dielectric layer having athrough hole is provided. An insulating material is filled into thethrough hole of the dielectric layer to form the insulating materiallayer, wherein the insulating material covers a portion of the firstpatterned circuit layer, and the dielectric layer covers a portion ofthe upper surface of the core layer.

In an embodiment of the invention, a material of the insulating materialis an ink, the laser resisting layer at least covers a portion of theinsulating material, and the release layer covers the laser resistinglayer.

In an embodiment of the invention, a method of forming the insulatingmaterial layer is a coating method, and a material of the insulatingmaterial layer is an ink.

In an embodiment of the invention, a material of the laser resistinglayer is a metal material, and the release layer at least covers thelaser resisting layer and the insulating material layer.

In an embodiment of the invention, the laser resisting layer iscompletely formed on the insulating material layer, and the releaselayer further covers a portion of the first patterned circuit layer.

In an embodiment of the invention, the manufacturing method of a circuitboard structure further includes the following. After the laser ablationprocess is performed on the first build-up circuit structure to removethe portion of the first build-up circuit structure and the releaselayer, the laser resisting layer is removed, and thereby a cavityexposing the insulating material layer and a portion of the uppersurface of the core layer is formed.

In an embodiment of the invention, the manufacturing method of a circuitboard structure further includes the following. While the laser ablationprocess is performed on the first build-up circuit structure to removethe portion of the first build-up circuit structure and the releaselayer, at least a portion of the laser resisting layer and at least aportion of the insulating material layer are removed, and thereby acavity exposing a portion of the insulating material layer, a portion ofthe laser resisting layer and a portion of the upper surface of the corelayer is formed.

In an embodiment of the invention, the manufacturing method of a circuitboard structure further includes the following. After the laser ablationprocess is performed on the first build-up circuit structure to removethe portion of the first build-up circuit structure and the releaselayer, the laser resisting layer and the insulating material layer areremoved, and thereby a cavity exposing a portion of the insulatingmaterial layer, a portion of the laser resisting layer and a portion ofthe upper surface of the core layer is formed.

In an embodiment of the invention, the cavity includes a plurality ofside walls having a concave-and-convex profile, a plane profile, or acombination thereof.

In an embodiment of the invention, a material of the laser resistinglayer is the same as a material of the insulating material layer. Thelaser resisting layer covers a portion of the insulating material layer,the release layer covers the insulating material layer and the laserresisting layer, and the cavity exposes the laser resisting layer, theinsulating material layer and a portion of the upper surface of the corelayer.

In an embodiment of the invention, the laser resisting layer has aring-shaped structure, and a portion of the first patterned circuitlayer is located in the ring-shaped structure.

In an embodiment of the invention, the first build-up circuit structureincludes at least one first dielectric layer, at least one firstpatterned conductive layer, and at least one first conductive throughhole structure passing through the first dielectric layer. The firstdielectric layer and the first patterned conductive layer are stacked insequence on the upper surface of the core layer, and the first patternedconductive layer is electrically connected to the first patternedcircuit layer through the first conductive through hole structure. Thesecond build-up circuit structure includes at least one seconddielectric layer, at least one second patterned conductive layer, and atleast one second conductive through hole structure passing through thesecond dielectric layer. The second dielectric layer and the secondpatterned conductive layer are stacked in sequence on the lower surfaceof the core layer, and the second patterned conductive layer iselectrically connected to the second patterned circuit layer through thesecond conductive through hole structure.

The circuit board structure according to the invention includes an innercircuit structure, a first build-up circuit structure and a secondbuild-up circuit structure. The inner circuit structure includes a corelayer having an upper surface and an opposite lower surface, a firstpatterned circuit layer disposed on the upper surface and a secondpatterned circuit layer disposed on the lower surface. The firstbuild-up circuit structure is disposed on the upper surface of the corelayer and covers the first patterned circuit layer, wherein the firstbuild-up circuit structure has a cavity, the cavity exposes a portion ofthe first patterned circuit layer and a portion of the upper surface ofthe core layer and includes a plurality of side walls, and the sidewalls have a concave-and-convex profile, or a combination ofconcave-and-convex and plane profiles. The second build-up circuitstructure is disposed on the lower surface of the core layer and coversthe second patterned circuit layer.

In an embodiment of the invention, the first build-up circuit structureincludes at least one first dielectric layer, at least one firstpatterned conductive layer, and at least one first conductive throughhole structure passing through the first dielectric layer. The firstdielectric layer and the first patterned conductive layer are stacked insequence on the upper surface of the core layer, and the first patternedconductive layer is electrically connected to the first patternedcircuit layer through the first conductive through hole structure. Thesecond build-up circuit structure includes at least one seconddielectric layer, at least one second patterned conductive layer, and atleast one second conductive through hole structure passing through thesecond dielectric layer. The second dielectric layer and the secondpatterned conductive layer are stacked in sequence on the lower surfaceof the core layer, and the second patterned conductive layer iselectrically connected to the second patterned circuit layer through thesecond conductive through hole structure.

The circuit board structure according to the invention includes an innercircuit structure, a first build-up circuit structure, an insulatingmaterial layer, a laser resisting layer, and a second build-up circuitstructure. The inner circuit structure includes a core layer having anupper surface and an opposite lower surface, a first patterned circuitlayer disposed on the upper surface and a second patterned circuit layerdisposed on the lower surface. The first build-up circuit structure isdisposed on the upper surface of the core layer and covers the firstpatterned circuit layer, wherein the first build-up circuit structurehas a cavity, and the cavity exposes a portion of the first patternedcircuit layer and a portion of the upper surface of the core layer. Theinsulating material layer is disposed on the portion of the firstpatterned circuit layer exposed by the cavity. The laser resisting layeris disposed on the insulating material layer, wherein the laserresisting layer has a ring-shaped structure, and a portion of the firstpatterned circuit layer is located in the ring-shaped structure. Thesecond build-up circuit structure is disposed on the lower surface ofthe core layer and covers the second patterned circuit layer.

In an embodiment of the invention, a material of the laser resistinglayer is a metal material.

In an embodiment of the invention, a material of the laser resistinglayer is the same as a material of the insulating material layer.

In an embodiment of the invention, the first build-up circuit structureincludes at least one first dielectric layer, at least one firstpatterned conductive layer, and at least one first conductive throughhole structure passing through the first dielectric layer. The firstdielectric layer and the first patterned conductive layer are stacked insequence on the upper surface of the core layer, and the first patternedconductive layer is electrically connected to the first patternedcircuit layer through the first conductive through hole structure. Thesecond build-up circuit structure includes at least one seconddielectric layer, at least one second patterned conductive layer, and atleast one second conductive through hole structure passing through thesecond dielectric layer. The second dielectric layer and the secondpatterned conductive layer are stacked in sequence on the lower surfaceof the core layer, and the second patterned conductive layer iselectrically connected to the second patterned circuit layer through thesecond conductive through hole structure.

Based on the above, during the manufacture of the circuit boardstructure of the invention, the laser resisting layer is formed on theinsulating material layer instead of the inner circuit structure.Therefore, subsequently, after the build-up circuit structures arefabricated, when the laser ablation process is performed to form thecavity that exposes the upper surface of the core layer of the innercircuit structure, the circuit layout of the core layer of the innercircuit structure will not be affected. That is, circuit designing canstill be carried out in the resulting cavity. Therefore, the circuitboard structure formed in the invention provides larger layout space.

To make the above features and advantages of the invention morecomprehensible, embodiments accompanied with drawings are described indetail as follows.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide further understanding,and are incorporated in and constitute a part of this specification. Thedrawings illustrate exemplary embodiments and, together with thedescription, serve to explain the principles of the invention.

FIG. 1A(a) to FIG. 1J illustrate cross-sectional schematic views of amanufacturing method of a circuit board structure according to anembodiment of the invention.

FIG. 2A to FIG. 2F illustrate cross-sectional schematic views of amanufacturing method of a circuit board structure according to anotherembodiment of the invention.

FIG. 3A to FIG. 3G illustrate cross-sectional schematic views of amanufacturing method of a circuit board structure according to anotherembodiment of the invention.

FIG. 4A to FIG. 4F illustrate cross-sectional schematic views of amanufacturing method of a circuit board structure according to anotherembodiment of the invention.

DETAILED DESCRIPTION OF DISCLOSED EMBODIMENTS

FIG. 1A(a) to FIG. 1J illustrate cross-sectional schematic views of amanufacturing method of a circuit board structure according to anembodiment of the invention. Referring first to FIG. 1A(a), with regardto the manufacturing method of a circuit board structure according tothe present embodiment, first of all, an inner circuit structure 110 isprovided, wherein the inner circuit structure 110 includes a core layer112 having an upper surface 111 and an opposite lower surface 113, afirst patterned circuit layer 114 disposed on the upper surface 111 anda second patterned circuit layer 116 disposed on the lower surface 113.As shown in FIG. 1A(a), the first patterned circuit layer 114 and thesecond patterned circuit layer 116 are electrically connected through atleast one conductive through hole 118 passing through the core layer112.

Next, referring to FIG. 1A(a) and FIG. 1B(a) together, an insulatingmaterial layer 120 is formed on a portion of the first patterned circuitlayer 114, wherein the insulating material layer 120 covers a portion ofthe upper surface 111. In detail, the step of forming the insulatingmaterial layer 120 includes the following. A dielectric layer 122 havinga through hole H is provided. Then, an insulating material 124 is filledinto the through hole H of the dielectric layer 122 to form theinsulating material layer 120, wherein the insulating material 124covers a portion of the first patterned circuit layer 114, and thedielectric layer 122 covers a portion of the upper surface 111 of thecore layer 112. Herein, a material of the insulating material 124 is,e.g., an ink, polypropylene (PP), polyethylene (PE), ABS (acrylonitrilebutadiene styrene) resin, polytetrafluoroethene (PTFE) or other suitablematerial.

It should be noted that the present embodiment does not impose anylimitation on the method of forming the insulating material layer 120.In other embodiments, e.g., with reference to FIG. 1A(b), an insulatingmaterial layer 120 a is formed on the upper surface 111 of the corelayer 112 by a coating method, wherein a material of the insulatingmaterial layer 120 a is, e.g., an ink, and this method still fallswithin the scope to be protected by the invention.

Next, referring to FIG. 1B(a) and FIG. 1B(b) together, a laser resistinglayer 130 is formed on at least a portion of the insulating materiallayers 120 and 120 a, wherein the laser resisting layer 130 at leastcovers a portion of the insulating material 124 of the insulatingmaterial layer 120 and a portion of the insulating material layer 120 a.As shown in FIG. 1B(a) and FIG. 1B(b), the laser resisting layer 130 ofthe present embodiment does not completely cover the insulating materiallayers 120 and 120 a. Specifically, the laser resisting layer 130 has aring-shaped structure, wherein an area where the laser resisting layer130 is present is an area where subsequent laser ablation is performed,and a portion of the first patterned circuit layer 114 is located in thering-shaped structure. Herein, a material of the laser resisting layer130 is, e.g., metal (copper, nickel, gold, silver, aluminum or othersuitable metal material), or non-metal (ceramic, quartz, carborundum orother suitable non-metal material).

To facilitate explanation, the steps subsequent to the step in FIG.1B(b) are described for exemplary purposes. Referring to FIG. 1C andFIG. 1D together, a release layer 140 is adhered to at least the laserresisting layer 130. As shown in FIG. 1D, the release layer 140 onlydirectly covers the laser resisting layer 130, and is spaced apart fromthe insulating material layer 120 a by an air gap G, wherein the releaselayer 140 does not cover the insulating material layer 120 a, and anedge of the release layer 140 is specifically aligned with an edge ofthe laser resisting layer 130.

Next, referring to FIG. 1E, a build-up process is performed so as tolaminate a first build-up circuit structure 150 a and a second build-upcircuit structure 150 b on the first patterned circuit layer 114 and thesecond patterned circuit layer 116, respectively, wherein the firstbuild-up circuit structure 150 a covers the release layer 140. Indetail, the first build-up circuit structure 150 a of the presentembodiment includes at least one first dielectric layer 152 a, at leastone first patterned conductive layer 154 a, and at least one firstconductive through hole structure 156 a passing through the firstdielectric layer 152 a. The first dielectric layer 152 a and the firstpatterned conductive layer 154 a are stacked in sequence on the uppersurface 111 of the core layer 112, and the first patterned conductivelayer 154 a is electrically connected to the first patterned circuitlayer 114 through the first conductive through hole structure 156 a. Thesecond build-up circuit structure 150 b includes at least one seconddielectric layer 152 b, at least one second patterned conductive layer154 b, and at least one second conductive through hole structure 156 bpassing through the second dielectric layer 152 b. The second dielectriclayer 152 b and the second patterned conductive layer 154 b are stackedin sequence on the lower surface 113 of the core layer 112, and thesecond patterned conductive layer 154 b is electrically connected to thesecond patterned circuit layer 116 through the second conductive throughhole structure 156 b.

Then, referring to FIG. 1F, FIG. 1G and FIG. 1H together, a laserablation process is performed on the first build-up circuit structure150 a to irradiate a laser beam L on the laser resisting layer 130 so asto remove a portion of the first build-up circuit structure 150 a andthe release layer 140, and thereby a cavity C1 at least exposing aportion of the upper surface 111 of the core layer 112 is formed. Indetail, as shown in FIG. 1F and FIG. 1G, the laser beam L is irradiatedonly on an area where the laser resisting layer 130 is disposed, and aportion of the first build-up circuit structure 150 a and the releaselayer 140 are removed by the irradiation with the laser beam L. Next, asshown in FIG. 1G and FIG. 1H, a lye (pH>12) or an organic solvent isused to remove the insulation material layer 120 a and the laserresisting layer 130 disposed thereon, so as to form the cavity C1exposing a portion of the upper surface 111 of the core layer 112. Atthis moment, the cavity C1 includes a plurality of side walls W1 and W2,and the side walls W1 and W2 specifically have a plane profile. However,the invention is not limited thereto. Up to this step, the manufactureof a circuit board structure 100 a has been completed.

It should be noted that in other embodiments, due to different positionson which the laser ablation is performed, the resulting cavity may haveside walls having different profiles. Referring to FIG. 1I, side wallsW11 and W21 of a cavity C11 specifically have a concave-and-convexprofile; or, referring to FIG. J, side walls W12 and W22 of a cavity C12specifically have a combination of concave-and-convex and planeprofiles. The above technical features still fall within the scope to beprotected by the invention.

In terms of structure, referring again to FIG. 1H, the circuit boardstructure 100 a of the present embodiment includes the inner circuitstructure 110, the first build-up circuit structure 150 a and the secondbuild-up circuit structure 150 b. The inner circuit structure 110includes the core layer 112 having the upper surface 111 and theopposite lower surface 113, the first patterned circuit layer 114disposed on the upper surface 111 and the second patterned circuit layer116 disposed on the lower surface 113. The first build-up circuitstructure 150 a is disposed on the upper surface 111 of the core layer112 and covers the first patterned circuit layer 114, wherein the firstbuild-up circuit structure 150 a has the cavity C1, the cavity C1exposes a portion of the first patterned circuit layer 114 and a portionof the upper surface 111 of the core layer 112 and includes a pluralityof side walls W1 and W2, and the side walls W1 and W2 specifically havea plane profile. The second build-up circuit structure 150 b is disposedon the lower surface 113 of the core layer 112 and covers the secondpatterned circuit layer 116.

It should be noted that the invention does not impose any limitation onthe profile of the side walls of the cavity. Referring to FIG. 1I, theside walls W11 and W21 of the cavity C11 of a circuit board structure100 a 1 specifically have a concave-and-convex profile; or, referring toFIG. 1J, the side walls W12 and W22 of the cavity C12 of a circuit boardstructure 100 a 2 specifically have a combination of concave-and-convexand plane profiles. The above technical features still fall within thescope to be protected by the invention.

During the manufacture of the circuit board structure 100 a of thepresent embodiment, the laser resisting layer 130 is formed on theinsulating material layer 120 a instead of the inner circuit structure110. Therefore, subsequently, after the first build-up circuit structure150 a and the second build-up circuit structure 150 b are fabricated,when the laser ablation process is performed to form the cavity C1 thatexposes the upper surface 111 of the core layer 112 of the inner circuitstructure 110, the circuit layout of the core layer 112 of the innercircuit structure 110 will not be affected. That is, circuit designingcan still be carried out in the resulting cavity C1. Therefore, thecircuit board structure 100 a formed in the present embodiment provideslarger layout space.

It should be noted that the reference numerals and a part of thecontents in the previous embodiment are used in the followingembodiments, in which identical reference numerals indicate identical orsimilar components, and repeated description of the same technicalcontents is omitted. For a detailed description of the omitted parts,reference can be found in the previous embodiment, and no repeateddescription is contained in the following embodiments.

FIG. 2A to FIG. 2F illustrate cross-sectional schematic views of amanufacturing method of a circuit board structure according to anotherembodiment of the invention. Referring to FIG. 2A, with regard to themanufacturing method of a circuit board structure according to thepresent embodiment, first of all, an inner circuit structure 110 b isprovided, wherein the inner circuit structure 110 b includes a corelayer 112 b having an upper surface 111 b and an opposite lower surface113 b, a first patterned circuit layer 114 b disposed on the uppersurface 111 b and a second patterned circuit layer 116 b disposed on thelower surface 113 b. As shown in FIG. 2A, the first patterned circuitlayer 114 b and the second patterned circuit layer 116 b areelectrically connected through at least one conductive through hole 118b passing through the core layer 112 b.

Next, referring to FIG. 2B, an insulating material layer 120 b is formedon a portion of the first patterned circuit layer 114 b, wherein theinsulating material layer 120 b covers a portion of the upper surface111 b. Herein, a material of the insulating material layer 120 b is,e.g., ink, polypropylene (PP), polyethylene (PE), ABS (acrylonitrilebutadiene styrene) resin, polytetrafluoroethene (PTFE) or other suitablematerial. Next, referring again to FIG. 2B, a laser resisting layer 130b is formed on the insulating material layer 120 b. As shown in FIG. 2B,the laser resisting layer 130 b of the present embodiment is completelyformed on the insulating material layer 120 b, but does not completelycover the insulating material layer 120 b. Specifically, the laserresisting layer 130 b has a ring-shaped structure, wherein an area wherethe laser resisting layer 130 b is present is an area where subsequentlaser ablation is performed, and a portion of the first patternedcircuit layer 114 b is located in the ring-shaped structure. Herein, amaterial of the laser resisting layer 130 b is, e.g., a metal material(e.g., copper, nickel, gold, silver, aluminum or other suitable metalmaterial), or non-metal (e.g., ceramic, quartz, carborundum or othersuitable non-metal material).

Next, referring to FIG. 2C, a release layer 140 b is adhered to at leastthe laser resisting layer 130 b, wherein the release layer 140 b atleast covers the laser resisting layer 130 b and the insulating materiallayer 120 b. As shown in FIG. 2C, the release layer 140 b directlycovers a portion of the first patterned circuit layer 114 b, a portionof the upper surface 111 b of the core layer 112 b, a portion of theinsulating material layer 120 b, and a portion of the laser resistinglayer 130 b. In other words, a portion of the laser resisting layer 130b and a portion of the insulating material layer 120 b are not coveredby the release layer 140 b.

Then, referring to FIG. 2D, a build-up process is performed so as tolaminate a first build-up circuit structure 150 a 1 and a secondbuild-up circuit structure 150 b 1 on the first patterned circuit layer114 b and the second patterned circuit layer 116 b, respectively,wherein the first build-up circuit structure 150 a 1 covers the releaselayer 140 b, a portion of the laser resisting layer 130 b and a portionof the insulating material layer 120 b. In detail, the first build-upcircuit structure 150 a 1 of the present embodiment includes at leastone first dielectric layer 152 a 1, at least one first patternedconductive layer 154 a 1, and at least one first conductive through holestructure 156 a 1 passing through the first dielectric layer 152 a 1.The first dielectric layer 152 a 1 and the first patterned conductivelayer 154 a 1 are stacked in sequence on the upper surface 111 b of thecore layer 112 b, and the first patterned conductive layer 154 a 1 iselectrically connected to the first patterned circuit layer 114 bthrough the first conductive through hole structure 156 a 1. The secondbuild-up circuit structure 150 b 1 includes at least one seconddielectric layer 152 b 1, at least one second patterned conductive layer154 b 1, and at least one second conductive through hole structure 156 b1 passing through the second dielectric layer 152 b 1. The seconddielectric layer 152 b 1 and the second patterned conductive layer 154 b1 are stacked in sequence on the lower surface 113 b of the core layer112 b, and the second patterned conductive layer 154 b 1 is electricallyconnected to the second patterned circuit layer 116 b through the secondconductive through hole structure 156 b 1.

Finally, referring to FIG. 2E and FIG. 2F together, a laser ablationprocess is performed on the first build-up circuit structure 150 a 1 toirradiate a laser beam L on the laser resisting layer 130 b so as toremove a portion of the first build-up circuit structure 150 a 1 and therelease layer 140 b, and thereby a cavity C2 at least exposing a portionof the upper surface 111 b of the core layer 112 b is formed. At thismoment, the cavity C2 also exposes a portion of the insulating materiallayer 120 b, a portion of the laser resisting layer 130 b and a portionof the first patterned circuit layer 114 b. Up to this step, themanufacture of a circuit board structure 100 b has been completed.

In terms of structure, referring again to FIG. 2F, the circuit boardstructure 100 b of the present embodiment includes the inner circuitstructure 110 b, the first build-up circuit structure 150 a 1, theinsulating material layer 120 b, the laser resisting layer 130 b, andthe second build-up circuit structure 150 b 1. The inner circuitstructure 110 b includes the core layer 112 b having the upper surface111 b and the opposite lower surface 113 b, the first patterned circuitlayer 114 b disposed on the upper surface 111 b and the second patternedcircuit layer 116 b disposed on the lower surface 113 b. The firstbuild-up circuit structure 150 a 1 is disposed on the upper surface 111b of the core layer 112 b and covers the first patterned circuit layer114 b, wherein the first build-up circuit structure 150 a has the cavityC2, and the cavity C2 exposes a portion of the first patterned circuitlayer 114 b and a portion of the upper surface 111 b of the core layer112 b. The insulating material layer 120 b is disposed on the portion ofthe first patterned circuit layer 114 b exposed by the cavity C2. Thelaser resisting layer 130 b is disposed on the insulating material layer120 b, wherein the laser resisting layer 130 b has a ring-shapedstructure, and a portion of the first patterned circuit layer 114 b islocated in the ring-shaped structure. Preferably, a material of thelaser resisting layer 130 b is, e.g., a metal material (e.g., copper,nickel, gold, silver, aluminum or other suitable metal material), ornon-metal (e.g., ceramic, quartz, carborundum or other suitablenon-metal material). The second build-up circuit structure 150 b 1 isdisposed on the lower surface 113 b of the core layer 112 b and coversthe second patterned circuit layer 116 b.

FIG. 3A to FIG. 3G illustrate cross-sectional schematic views of amanufacturing method of a circuit board structure according to anotherembodiment of the invention. Referring to FIG. 3A, with regard to themanufacturing method of a circuit board structure according to thepresent embodiment, first of all, an inner circuit structure 110 b isprovided, wherein the inner circuit structure 110 b includes a corelayer 112 b having an upper surface 111 b and an opposite lower surface113 b, a first patterned circuit layer 114 b disposed on the uppersurface 111 b and a second patterned circuit layer 116 b disposed on thelower surface 113 b. As shown in FIG. 3A, the first patterned circuitlayer 114 b and the second patterned circuit layer 116 b areelectrically connected through at least one conductive through hole 118b passing through the core layer 112 b.

Next, referring to FIG. 3B, an insulating material layer 120 c is formedon a portion of the first patterned circuit layer 114 b, wherein theinsulating material layer 120 c covers a portion of the upper surface111 b. Herein, a material of the insulating material layer 120 c is,e.g., ink, polypropylene (PP), polyethylene (PE), ABS (acrylonitrilebutadiene styrene) resin, polytetrafluoroethene (PTFE) or other suitablematerial. Next, referring again to FIG. 3B, a laser resisting layer 130c is formed on a portion of the insulating material layer 120 c. Asshown in FIG. 3B, the laser resisting layer 130 c of the presentembodiment is not completely formed on the insulating material layer 120c but is formed on only a portion of the insulating material layer 120c, and does not completely cover the insulating material layer 120 c.Specifically, the laser resisting layer 130 c has a ring-shapedstructure, wherein an area where the laser resisting layer 130 c ispresent is an area where subsequent laser ablation is performed, and aportion of the first patterned circuit layer 114 b is located in thering-shaped structure. Moreover, the first patterned circuit layer 114 blocated in the ring-shaped structure has no laser resisting layer 130 cthereon. Herein, a material of the laser resisting layer 130 c is, e.g.,a metal material (e.g., copper, nickel, gold, silver, aluminum or othersuitable metal material), or non-metal (e.g., ceramic, quartz,carborundum or other suitable non-metal material).

Next, referring to FIG. 3C, a release layer 140 c is adhered to thelaser resisting layer 130 c and the insulating material layer 120 c,wherein the release layer 140 c directly covers the laser resistinglayer 130 c and the insulating material layer 120 c, and exposes aportion of the laser resisting layer 130 c and a portion of theinsulating material layer 120 c.

Next, referring to FIG. 3D, a build-up process is performed so as tolaminate a first build-up circuit structure 150 a 1 and a secondbuild-up circuit structure 150 b 1 on the first patterned circuit layer114 b and the second patterned circuit layer 116 b, respectively,wherein the first build-up circuit structure 150 a 1 covers the releaselayer 140 c, a portion of the laser resisting layer 130 c and a portionof the insulating material layer 120 c. In detail, the first build-upcircuit structure 150 a 1 of the present embodiment includes at leastone first dielectric layer 152 a 1, at least one first patternedconductive layer 154 a 1, and at least one first conductive through holestructure 156 a 1 passing through the first dielectric layer 152 a 1.The first dielectric layer 152 a 1 and the first patterned conductivelayer 154 a 1 are stacked in sequence on the upper surface 111 b of thecore layer 112 b, and the first patterned conductive layer 154 a 1 iselectrically connected to the first patterned circuit layer 114 bthrough the first conductive through hole structure 156 a 1. The secondbuild-up circuit structure 150 b 1 includes at least one seconddielectric layer 152 b 1, at least one second patterned conductive layer154 b 1, and at least one second conductive through hole structure 156 b1 passing through the second dielectric layer 152 b 1. The seconddielectric layer 152 b 1 and the second patterned conductive layer 154 b1 are stacked in sequence on the lower surface 113 b of the core layer112 b, and the second patterned conductive layer 154 b 1 is electricallyconnected to the second patterned circuit layer 116 b through the secondconductive through hole structure 156 b 1.

Then, referring to FIG. 3E and FIG. 3F together, a laser ablationprocess is performed on the first build-up circuit structure 150 a 1 toirradiate a laser beam L on the laser resisting layer 130 c so as toremove a portion of the first build-up circuit structure 150 a 1 and therelease layer 140 c, and thereby a cavity C3 at least exposing a portionof the upper surface 111 b of the core layer 112 b is formed. At thismoment, the cavity C3 also exposes a portion of the insulating materiallayer 120 c and a portion of the laser resisting layer 130 c.

Finally, referring to FIG. 3F and FIG. 3G together, the laser resistinglayer 130 c is removed so as to form the cavity C3 including side wallsW31 and W32 having a concave-and-convex profile, wherein a method ofremoving the laser resisting layer 130 c is, e.g., dissolving theinsulating material layer 120 c on the lower side in a lye or an organicsolvent so that the laser resisting layer 130 c naturally falls down. Upto this step, the manufacture of a circuit board structure 100 c hasbeen completed.

In terms of structure, referring again to FIG. 3G, the circuit boardstructure 100 c of the present embodiment is similar to the circuitboard structure 100 b in FIG. 2F, and the differences therebetween liein that the circuit board structure 100 c of the present embodimentincludes no laser resisting layer 130 c, the first patterned circuitlayer 114 b exposed by the cavity C3 is entirely covered by theinsulating material layer 120 c, and the side walls W31 and W32 of thecavity C3 have a concave-and-convex profile.

FIG. 4A to FIG. 4F illustrate cross-sectional schematic views of amanufacturing method of a circuit board structure according to anotherembodiment of the invention. Referring to FIG. 4A, with regard to themanufacturing method of a circuit board structure according to thepresent embodiment, first of all, an inner circuit structure 110 b isprovided, wherein the inner circuit structure 110 b includes a corelayer 112 b having an upper surface 111 b and an opposite lower surface113 b, a first patterned circuit layer 114 b disposed on the uppersurface 111 b and a second patterned circuit layer 116 b disposed on thelower surface 113 b. As shown in FIG. 4A, the first patterned circuitlayer 114 b and the second patterned circuit layer 116 b areelectrically connected through at least one conductive through hole 118b passing through the core layer 112 b.

Next, referring to FIG. 4B, an insulating material layer 120 d is formedon a portion of the first patterned circuit layer 114 b, wherein theinsulating material layer 120 d covers a portion of the upper surface111 b. Herein, a material of the insulating material layer 120 d is,e.g., ink, polypropylene (PP), polyethylene (PE), ABS (acrylonitrilebutadiene styrene) resin, polytetrafluoroethene (PTFE) or other suitablematerial. Next, referring again to FIG. 4B, a laser resisting layer 130d is formed on a portion of the insulating material layer 120 d. Asshown in FIG. 4B, the laser resisting layer 130 d of the presentembodiment is not completely formed on the insulating material layer 120d but is formed on only a portion of the insulating material layer 120d, and does not completely cover the insulating material layer 120 d.Specifically, the laser resisting layer 130 d has a ring-shapedstructure, wherein an area where the laser resisting layer 130 d ispresent is an area where subsequent laser ablation is performed, and aportion of the first patterned circuit layer 114 b is located in thering-shaped structure. Moreover, the first patterned circuit layer 114 blocated in the ring-shaped structure has no laser resisting layer 130 dthereon. Particularly, a material of the laser resisting layer 130 d isthe same as the material of the insulating material layer 120 d. Inother words, the material of the laser resisting layer 130 d is alsometal (e.g., copper, nickel, gold, silver, aluminum or other suitablemetal material), or non-metal (e.g., ceramic, quartz, carborundum orother suitable non-metal material).

Next, referring to FIG. 4C, a release layer 140 d is adhered to thelaser resisting layer 130 d and the insulating material layer 120 d,wherein the release layer 140 d directly covers the laser resistinglayer 130 d and the insulating material layer 120 d, and exposes aportion of the laser resisting layer 130 d.

Next, referring to FIG. 4D, a build-up process is performed so as tolaminate a first build-up circuit structure 150 a 1 and a secondbuild-up circuit structure 150 b 1 on the first patterned circuit layer114 b and the second patterned circuit layer 116 b, respectively,wherein the first build-up circuit structure 150 a 1 covers the releaselayer 140 d, a portion of the laser resisting layer 130 d and a portionof the insulating material layer 120 d. In detail, the first build-upcircuit structure 150 a 1 of the present embodiment includes at leastone first dielectric layer 152 a 1, at least one first patternedconductive layer 154 a 1, and at least one first conductive through holestructure 156 a 1 passing through the first dielectric layer 152 a 1.The first dielectric layer 152 a 1 and the first patterned conductivelayer 154 a 1 are stacked in sequence on the upper surface 111 b of thecore layer 112 b, and the first patterned conductive layer 154 a 1 iselectrically connected to the first patterned circuit layer 114 bthrough the first conductive through hole structure 156 a 1. The secondbuild-up circuit structure 150 b 1 includes at least one seconddielectric layer 152 b 1, at least one second patterned conductive layer154 b 1, and at least one second conductive through hole structure 156 b1 passing through the second dielectric layer 152 b 1. The seconddielectric layer 152 b 1 and the second patterned conductive layer 154 b1 are stacked in sequence on the lower surface 113 b of the core layer112 b, and the second patterned conductive layer 154 b 1 is electricallyconnected to the second patterned circuit layer 116 b through the secondconductive through hole structure 156 b 1.

Then, referring to FIG. 4E and FIG. 4F together, a laser ablationprocess is performed on the first build-up circuit structure 150 a 1 toirradiate a laser beam L on the laser resisting layer 130 d so as toremove a portion of the first build-up circuit structure 150 a 1 and therelease layer 140 d, and thereby a cavity C4 at least exposing a portionof the upper surface 111 b of the core layer 112 b is formed. While thelaser ablation process is performed on the first build-up circuitstructure 150 a 1 to remove the portion of the first build-up circuitstructure 150 a 1 and the release layer 140 d, a portion of the laserresisting layer 130 d and a portion of the insulating material layer 120d are removed, and thereby the cavity C4 exposing a portion of theinsulating material layer 120 d, a portion of the laser resisting layer130 d and a portion of the upper surface 111 b of the core layer 112 bis formed. In other words, the cavity C4 also exposes a portion of theinsulating material layer 120 d and a portion of the laser resistinglayer 130 d. Up to this step, the manufacture of a circuit boardstructure 100 d has been completed.

In terms of structure, referring again to FIG. 4F, the circuit boardstructure 100 d of the present embodiment is similar to the circuitboard structure 100 b in FIG. 2F, and the differences therebetween liein that in the circuit board structure 100 d of the present embodiment,the material of the laser resisting layer 130 d is the same as thematerial of the insulating material layer 120 d, and the laser resistinglayer 130 d has an opening T extending to the insulating material layer120 d due to the laser ablation. The cavity C4 exposes a portion of thelaser resisting layer 130 d, a portion of the insulating material layer120 d and a portion of the upper surface 111 b of the core layer 112 b.

In summary, during the manufacture of the circuit board structure of theinvention, the laser resisting layer is formed on the insulatingmaterial layer instead of the inner circuit structure. Therefore,subsequently, after the build-up circuit structures are fabricated, whenthe laser ablation process is performed to form the cavity that exposesthe upper surface of the core layer of the inner circuit structure, thecircuit layout of the core layer of the inner circuit structure will notbe affected. That is, circuit designing can still be carried out in theresulting cavity. Therefore, the circuit board structure formed in theinvention provides larger layout space.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the structure of thedisclosed embodiments without departing from the scope or spirit of theinvention. In view of the foregoing, it is intended that the inventioncover modifications and variations of this invention provided they fallwithin the scope of the following claims and their equivalents.

1. A manufacturing method of a circuit board structure, comprising:providing an inner circuit structure, the inner circuit structurecomprising a core layer having an upper surface and an opposite lowersurface, a first patterned circuit layer disposed on the upper surfaceand a second patterned circuit layer disposed on the lower surface;forming an insulating material layer on a portion of the first patternedcircuit layer, wherein the insulating material layer covers a portion ofthe upper surface; forming a laser resisting layer on at least a portionof the insulating material layer; adhering a release layer to the laserresisting layer; performing a build-up process so as to laminate a firstbuild-up circuit structure and a second build-up circuit structure onthe first patterned circuit layer and the second patterned circuitlayer, respectively, wherein the first build-up circuit structure coversthe release layer, and performing a laser ablation process on the firstbuild-up circuit structure to irradiate a laser beam on the laserresisting layer so as to remove a portion of the first build-up circuitstructure and the release layer, thereby forming a cavity at leastexposing a portion of the upper surface of the core layer.
 2. Themanufacturing method of the circuit board structure as recited in claim1, wherein the step of forming the insulating material layer comprises:providing a dielectric layer having a through hole; and filling aninsulating material into the through hole of the dielectric layer toform the insulating material layer, wherein the insulating materialcovers a portion of the first patterned circuit layer, and thedielectric layer covers a portion of the upper surface of the corelayer.
 3. The manufacturing method of the circuit board structure asrecited in claim 2, wherein a material of the insulating material is anink, the laser resisting layer at least covers a portion of theinsulating material, and the release layer covers the laser resistinglayer.
 4. The manufacturing method of the circuit board structure asrecited in claim 1, wherein a method of forming the insulating materiallayer is a coating method, and a material of the insulating materiallayer is an ink.
 5. The manufacturing method of the circuit boardstructure as recited in claim 1, wherein a material of the laserresisting layer is a metal material, and the release layer at leastcovers the laser resisting layer and the insulating material layer. 6.The manufacturing method of the circuit board structure as recited inclaim 5, wherein the laser resisting layer is completely formed on theinsulating material layer, and the release layer further covers aportion of the first patterned circuit layer.
 7. The manufacturingmethod of the circuit board structure as recited in claim 5, furthercomprising: after performing the laser ablation process on the firstbuild-up circuit structure to remove the portion of the first build-upcircuit structure and the release layer, removing the laser resistinglayer, so as to form a cavity exposing the insulating material layer anda portion of the upper surface of the core layer.
 8. The manufacturingmethod of the circuit board structure as recited in claim 1, furthercomprising: while performing the laser ablation process on the firstbuild-up circuit structure to remove the portion of the first build-upcircuit structure and the release layer, removing at least a portion ofthe laser resisting layer and at least a portion of the insulatingmaterial layer, so as to form a cavity exposing a portion of theinsulating material layer, a portion of the laser resisting layer and aportion of the upper surface of the core layer.
 9. The manufacturingmethod of the circuit board structure as recited in claim 1, furthercomprising: after performing the laser ablation process on the firstbuild-up circuit structure to remove the portion of the first build-upcircuit structure and the release layer, removing the laser resistinglayer and the insulating material layer, so as to form a cavity exposinga portion of the insulating material layer, a portion of the laserresisting layer and a portion of the upper surface of the core layer.10. The manufacturing method of the circuit board structure as recitedin claim 9, wherein the cavity comprises a plurality of side wallshaving a concave-and-convex profile, a plane profile, or a combinationthereof.
 11. The manufacturing method of the circuit board structure asrecited in claim 1, wherein a material of the laser resisting layer isthe same as a material of the insulating material layer, the laserresisting layer covers a portion of the insulating material layer, therelease layer covers the insulating material layer and the laserresisting layer, and the cavity exposes the laser resisting layer, theinsulating material layer and the portion of the upper surface of thecore layer.
 12. The manufacturing method of the circuit board structureas recited in claim 1, wherein the laser resisting layer has aring-shaped structure, and a portion of the first patterned circuitlayer is located in the ring-shaped structure.
 13. The manufacturingmethod of the circuit board structure as recited in claim 1, wherein thefirst build-up circuit structure comprises at least one first dielectriclayer, at least one first patterned conductive layer, and at least onefirst conductive through hole structure passing through the firstdielectric layer, the first dielectric layer and the first patternedconductive layer are stacked in sequence on the upper surface of thecore layer, and the first patterned conductive layer is electricallyconnected to the first patterned circuit layer through the firstconductive through hole structure, and wherein the second build-upcircuit structure comprises at least one second dielectric layer, atleast one second patterned conductive layer, and at least one secondconductive through hole structure passing through the second dielectriclayer, the second dielectric layer and the second patterned conductivelayer are stacked in sequence on the lower surface of the core layer,and the second patterned conductive layer is electrically connected tothe second patterned circuit layer through the second conductive throughhole structure.
 14. A circuit board structure, comprising: an innercircuit structure, comprising a core layer having an upper surface andan opposite lower surface, a first patterned circuit layer disposed onthe upper surface and a second patterned circuit layer disposed on thelower surface; a first build-up circuit structure, disposed on the uppersurface of the core layer and covering the first patterned circuitlayer, wherein the first build-up circuit structure has a cavity, thecavity exposes a portion of the first patterned circuit layer and aportion of the upper surface of the core layer, and the cavity comprisesa plurality of side walls, and the side walls have a concave-and-convexprofile, or a combination of concave-and-convex and plane profiles; anda second build-up circuit structure, disposed on the lower surface ofthe core layer and covering the second patterned circuit layer.
 15. Thecircuit board structure as recited in claim 14, wherein the firstbuild-up circuit structure comprises at least one first dielectriclayer, at least one first patterned conductive layer, and at least onefirst conductive through hole structure passing through the firstdielectric layer, the first dielectric layer and the first patternedconductive layer are stacked in sequence on the upper surface of thecore layer, and the first patterned conductive layer is electricallyconnected to the first patterned circuit layer through the firstconductive through hole structure, and wherein the second build-upcircuit structure comprises at least one second dielectric layer, atleast one second patterned conductive layer, and at least one secondconductive through hole structure passing through the second dielectriclayer, the second dielectric layer and the second patterned conductivelayer are stacked in sequence on the lower surface of the core layer,and the second patterned conductive layer is electrically connected tothe second patterned circuit layer through the second conductive throughhole structure.
 16. A circuit board structure, comprising: an innercircuit structure, comprising a core layer having an upper surface andan opposite lower surface, a first patterned circuit layer disposed onthe upper surface and a second patterned circuit layer disposed on thelower surface; a first build-up circuit structure, disposed on the uppersurface of the core layer and covering the first patterned circuitlayer, wherein the first build-up circuit structure has a cavity, andthe cavity exposes a portion of the first patterned circuit layer and aportion of the upper surface of the core layer, an insulating materiallayer, disposed on the portion of the first patterned circuit layerexposed by the cavity; a laser resisting layer, disposed on theinsulating material layer, wherein the laser resisting layer has aring-shaped structure, and a portion of the first patterned circuitlayer is located in the ring-shaped structure; and a second build-upcircuit structure, disposed on the lower surface of the core layer andcovering the second patterned circuit layer.
 17. The circuit boardstructure as recited in claim 16, wherein a material of the laserresisting layer is a metal material.
 18. The circuit board structure asrecited in claim 16, wherein a material of the laser resisting layer isthe same as a material of the insulating material layer.
 19. The circuitboard structure as recited in claim 16, wherein the first build-upcircuit structure comprises at least one first dielectric layer, atleast one first patterned conductive layer, and at least one firstconductive through hole structure passing through the first dielectriclayer, the first dielectric layer and the first patterned conductivelayer are stacked in sequence on the upper surface of the core layer,and the first patterned conductive layer is electrically connected tothe first patterned circuit layer through the first conductive throughhole structure, and wherein the second build-up circuit structurecomprises at least one second dielectric layer, at least one secondpatterned conductive layer, and at least one second conductive throughhole structure passing through the second dielectric layer, the seconddielectric layer and the second patterned conductive layer are stackedin sequence on the lower surface of the core layer, and the secondpatterned conductive layer is electrically connected to the secondpatterned circuit layer through the second conductive through holestructure.